Re: gaussian distribution pgbench -- splits v4

From: Mitsumasa KONDO <kondo(dot)mitsumasa(at)gmail(dot)com>
To: Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, Andres Freund <andres(at)2ndquadrant(dot)com>, Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: gaussian distribution pgbench -- splits v4
Date: 2014-07-24 15:44:09
Message-ID: CADupcHUrKZRfZifVG-fc-2mEtouMh0QPU+aSv_Pj9Cagzy8POg@mail.gmail.com
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Hi,

Thank you for your grate documentation and fix working!!!
It becomes very helpful for understanding our feature.

I add two feature in gauss_B_4.patch.

1) Add gaussianProbability() function
It is same as exponentialProbability(). And the feature is as same as
before.

2) Add result of "max/min percent of the range"
It is almost same as --exponential option's result. However, max percent of
the range is center of distribution
and min percent of the range is most side of distribution.
Here is the output example,

+ pgbench_account's aid selected with a truncated gaussian distribution

+ standard deviation threshold: 5.00000

+ decile percents: 0.0% 0.1% 2.1% 13.6% 34.1% 34.1% 13.6% 2.1% 0.1% 0.0%

+ probability of max/min percent of the range: 4.0% 0.0%

And I add the explanation about this in the document.

I'm very appreciate for your works!!!

Best regards,

--

Mitsumasa KONDO

Attachment Content-Type Size
gauss_B_5.patch application/octet-stream 14.9 KB

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